The report that did not add up
A blended sales report says 4 rows and 1,250 pence. The till system says 5 rows. Somebody asks: "Which is right?"
An audit answers that. It checks the result against what it should be, and writes down what it found.
Key words
| Word | What it means |
|---|---|
| Audit | a planned check of a result against what is needed |
| Validation | checking values are in a sensible format |
| Verification | checking a result is correct, by cross-checking |
| Control total | a count or sum from the source, to compare with |
| Reconciliation | matching two sets of figures and explaining any gap |
| Requirement | something the result must do or show |
| Audit record | a written note of findings and what to do next |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can audit a result and record what I found.
Starter
Have a go
Starter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Identify the requirements of the audit
Decide what the audit must show. Which result is checked? Against what? Who reads the answer?
Turn that into a short list of checks, each one clear enough to pass or fail.
An audit checklist
| Check | Type | Pass when |
|---|---|---|
| Dates are year-month-day | Validation | Every date has the agreed format |
| No missing amounts | Validation | No empty value in pence |
| Row count equals the source | Verification | Counts match the control total |
| Total pence equals the source | Verification | Sums match the control total |
The cells students fill in are left blank in this preview.
Validate: is the format right?
Validation checks that the result is in a format that suits the requirements. Dates look like dates. Numbers are numbers. Codes follow the pattern.
It does not prove the figures are right. It proves they are shaped right.
Try it: find the badly formatted date
select sale_id, sold_on
from blended
where not regexp_matches(sold_on, '^[0-9]{4}-[0-9]{2}-[0-9]{2}$');
-- Row 3 uses the day first. It fails the check.
Check
Have a go
Check
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.